UE4 Landscape Question

Hi, I am looking into UE4 and noticed on the vehicle game landscape the texture that is the road cannot be painted over with another texture. I thought it was a separate mesh but when i move the terrain it moves with the terrain. I look into the landscape textures and dont see the texture. I am baffled how this texture was applied to the landscape.

http://i.imgur.com/RqFP2O7.jpg